Division 22 - Plumbing

  1. This information provides guidelines for the design and construction of plumbing systems within buildings. Additional requirements for heating, ventilating, and air conditioning systems (HVAC); fire sprinkler systems, steam distribution systems, natural gas distribution systems, and other fuel systems; civil site utilities (water, sanitary, storm, irrigation); and temporary facilities and controls are covered in other parts of these standards or are available from the WWU project representative.
  2. WWU project representative, Facilities Maintenance (FM), Public Safety Office, and Environmental Health and Safety Office shall approve selection of materials, means, and methods. Unless otherwise approved, the design intent requires means and methods that provide minimal disruption to adjacent building activities and operations.
  3. When working in or adjacent to occupied buildings, require means and methods that protect occupants from exposure to noise, dust, traffic, and other hazards.
  4. WWU project representative shall inform FM and other campus departments or groups affected by the work.
  5. General:
    • Stop valves: Provide in the water connections to each fixture in accessible locations. Utilize washerless ¼ turn stops with handle. Prefer threaded connections. Minimize compression fittings.
    • Escutcheons: Provide at each wall, floor, and ceiling penetration in exposed finish locations and within cabinets and millwork. Escutcheons shall be chrome plated metal only. Prohibit plastic escutcheons.
    • Floor drains: Provide in all mechanical rooms, baths, toilet rooms, kitchens, laundry rooms, shower drying areas, swimming areas, whirlpool rooms, saunas, and service sink closets with wall mounted sink.
    • Trap primers: Require readily accessible trap primers for floor drains in mechanical rooms and unoccupied spaces. Prefer Jay R. Smith Prime-Eze Water Saver Trap Primer Model 2698 or approved equal.  Prohibit PPP automatic metering trap primers.
    • Trap primers are not required in rooms that will be cleaned regularly such as toilet rooms, shower rooms, etc. Consider specifying and/or detailing a deeper trap where trap primer is not provided to lengthen the evaporation time.   Confirm cleaning schedule and use of water with the FM project representative/custodial department responsible for cleaning the area.
    • Hose bibbs: Require within 25' ft. (8.3 m) of service entrances, in mechanical rooms over 400 sq. ft. (40 sq m), in all restrooms, and on exterior of buildings at a maximum of 100’ (30m) intervals. Interior hose bibbs shall have lockable vandal proof valve stems. Include atmosphere vacuum breakers (removable and repairable) and separate isolation valve for each.  Require all exterior hose bibbs to be freeze proof.
    • Shut-off and drain valves: Required at the bottom of all risers so that branches may be isolated for repairs without draining down the complete system. Require labeled access doors for all shut off and drain valves.
  6. The following information should be shown on drawings:
    • Configuration and sizes for all piping systems.
    • Whether piping is run above or below ground, floors, and ceilings, and whether concealed or exposed.  Show how piping is supported. Show direction of slope.
    • Locations of shut-off ball valves (clearly labeled) for each restroom, each floor and each piece of equipment.  Show drain valves after shutoffs.
    • Locations and sizes of access panels to each valve, cleanout, etc.
    • Location and type of each plumbing fixture.
    • Details for attaching wall-hung fixtures to walls.
    • Locations, sizes and types of cleanouts in building, in crawl spaces or exterior of buildings.
    • Location of acid resistant DWV piping, cleanouts, traps, drains and accessories.
    • Locations, sizes, and typical details for trap primers.  Show access doors.
    • Typical detail sections through roof drain, floor drain, floor sink and individual source grease trap.
    • Detail sections through exterior grease interceptors.
    • Location and size of water hammer arresters or air chambers.
    • Capacity, size, by-pass valves and piping for water meters and detail of water meter box.
    • Detail of building domestic water main service entrance piping – backflow preventer (show adequate access, elevation, anchors), bypass, strainer with gauges on inlet and outlet, (with blow-off outlet, pipe nipple, and ball valve) in water supply to each building.
  7. Require appropriate testing and flushing of system. See “DIVISION 23 Testing, Adjusting, and Balancing” standard.
  8. Require appropriate insulation for piping.   See “DIVISION 23 Mechanical Insulation” standard.
  9. Require appropriate hangers per UPC/ASTM. Size appropriately to accommodate insulation. Provide stainless steel hangers for below grade piping supported from structural slabs.
  10. Require hot and cold-water supply within laboratory buildings and laboratory rooms to be piped separately from the domestic water supply.  Isolate systems with backflow device.
  11. Require recirculation for domestic hot water and laboratory water with no dead-ends.
  12. Plumbing fixtures:
    • Vitreous china fixtures:  Prefer Kohler or approved equal American Standard Murro Universal Design. Prefer white Pennington K-2196-4 drop-in or Brenham K-1999-4-0 lavatory sinks.
    • Stainless steel countertop kitchen sinks:  Elkay or approved equal.
    • Lab, kitchen dining hall, and janitor sink faucets:  Chicago or approved equal.
    • Shower, lavatory, and kitchen sinks:  Moen faucets or approved equal (Delta, Symonds brands not acceptable). Prefer lavatory sinks with Moen Faucets model 8416.
    • Flushometers: Sloan Royal. 
    • Water Closets: Prefer Kohler (standard height K96053-SS-0, ADA height K96057-SS-0) floor mounted/floor discharge water closets with manually operated Sloan flushometers or approved equal American Standard Madera FloWise 3461-001.  Wall mounted is acceptable if remodel projects require matching style in balance of restroom. Avoid tank type water closets.
    • Bemis 1955C seats or approved equal for water closets. 
    • Urinals: Prefer Kohler brand with manually operated Sloan flushometers. Avoid waterless urinals. 
    • Automatic shutoff lavatory faucets:  Prohibit automatic shutoff lavatory faucets.
    • Porcelain cast iron sinks, tubs, etc.:  Prefer Kohler.
    • Lavatory widespread faucets: Prefer Chicago, Wolverine, or approved equal. Provide grate style drains at public restrooms. Within University Residences, prefer non-widespread faucets with pop-up style drains.
    • Drinking fountains:  Prefer Elkay (model# EZSTL8WSLK) ADA compliant water cooler, non-filtered bi-level light gray granite color with Flexi-Guard Safety Bubbler spout and no-touch bottle filling station. Single level water cooler (model# EZS8WSLK with same attributes as described above) is acceptable upon approval from CPD project manager. 
    • Service sinks: Prefer Fiat TSB3000501 Mop Service Basin.
    • Service sink faucets: Require integral check valve, stops and vacuum breaker to prevent backflow when hose is attached. Chicago faucet or approved equal. Prefer part number 897-MPRCF.
    • Grab bars peened: Bobbrick B-6806 or approved equal
    • Emergency shower and eyewash:
      • Acceptable manufacturer:  Hawes, Guardian, Watersaver or approved substitute.
      • Require emergency shower and eyewash or emergency eyewash in all laboratories, shops, and workrooms using chemical or hazardous materials. Comply with latest WISHA/OSHA rules.
      • Require tempered water 60-100°F (15-29°C) as defined in ANSI Z358.1-2014.
      • Flow monitoring sensor is required and connected to the Fire Alarm system that reports to University Police Dispatch Center.
  13. Pipe and fittings:  See “DIVISION 20 Basic Methods and Materials” standard.
  14. Backflow preventer:
    • Design and install in accordance with local and State codes.
    • Require for domestic, building fire, lawn hydrant, and irrigation, lab water, mechanical heating, and cooling water makeup systems.
    • All backflow preventer installations are to have a strainer upstream of inlet.
    • Require double detector check (DDC) backflow with bypass meter on fire mains.
    • Require water lines to be flushed prior to backflow preventer installation.
    • Require redundancy to allow shut down during required annual testing.
    • Size relief drains for maximum flow and pipe relief to nearby drain per local and State code.
    • Acceptable manufacturers: Febco, Watts, Wilkins and Zurn.
    • Software shall be provided with no-charge lifetime communications.
  15. Water meters:
    • Require for all building water supply.
    • Provide separate flow meters for heating and chilled water makeup and irrigation systems to allow separate billing for these systems.
    • Flow meters shall read in gallons.
    • Acceptable manufacturers: Onicon 2, Hayes, Zurn, or approved equal.
  16. Natural Gas Meter:
    • Acceptable manufacturer: American Meter aC-250NX Meter with Pulser or approved equal.
  17. Vacuum Pump:
    • Acceptable manufacturers: Busch Rotary Screw, Powerex or approved equal.
  18. Domestic water heater:
    • Require semi-instantaneous unit utilizing low pressure steam as the heating source.
    • Design for minimum working pressure of 150 psig (1034kPa).
    • Provide expansion tanks with water heater installations where required.
    • Require ASME rated and National Board stamped.
    • Provide seismically restrained support.
    • Acceptable manufacturers:  AERCO or Armstrong.
    • Provide ASME rated pressure and temperature relief valves, inlet and outlet thermometers, pressure gauges upstream and downstream of the control valve, bronze body circulating pump, control valve, storage/accumulator tank, and all auxiliaries necessary to compose a complete working unit.
    • Provide control diagram and sequence of operation to be compatible with the University’s BAC system.
    • Provide approved anti-scald temperature level/alarm systems in University Residence environment or academic buildings with shower/bath.
  19. Exterior grease interceptors:
    • This standard does not apply to interior in-floor kitchen grease traps which shall be limited to serving a single source fixture.
    • Comply with City of Bellingham requirements for design of interceptor.
    • Require witness tests for water tightness and hydrostatic testing.
    • Require readily accessible concrete interceptor located on the exterior of the building for commercial kitchen and dining facilities. Prohibit masonry, polyethylene or fiberglass construction.
    • Tank construction shall be watertight. Manhole cover shall be gas tight and shall be sized greater than 30" (750mm) diameter.
    • Require minimum 1000-gallon capacity. Do not oversize. Provide calculations utilizing University historical data for sizing and emptying schedule.
    • Require cleanouts in inlet and outlet piping. Coordinate the need for system additives with the Facilities Management project representative, Environmental Health and Safety, and the City of Bellingham.
    • Require discharge piping from exterior grease interceptors to be piped to an exterior sanitary system. Evaluate the condition (airtight) and capacity (surge volume) of downstream sanitary system accepting discharge from interceptor    Prefer all discharge connection direct to manholes. Prohibit reconnection of discharge piping to the interior building sanitary system.
    • Comply with City of Bellingham requirements for venting to minimize odors. Prohibit reconnection of vent piping to interior building vent system.
    • Minimize odors and spills which may generate health and safety complaints.
    • Require concrete pad for pumper truck with lined spill containment. Require appropriate traffic loading design (fire lanes or parking lots). Pumper truck pad shall be located within 50’ of the grease interceptor.
    • Require a freeze-proof hose bibb, electrical power connection, adequate lighting (appropriately classified) and safety signage to facilitate maintenance.

Latest update

2023-11-06